- You can also split a window horizontally or vertically by clicking
-@kbd{C-Mouse-2} in the mode line or the scroll bar. If you click on
-the mode line, that puts the vertical divider where you click; if you
-click in the scroll bar, that puts the new mode-line where you click.
+ If you click @kbd{C-Mouse-2} in the mode line of a window, that
+splits the window, putting a vertical divider where you click.
+Depending on how Emacs is compiled, you can also split a window by
+clicking @kbd{C-Mouse-2} in the scroll bar, which puts a horizontal
+divider where you click (this feature does not work when Emacs uses
+GTK+ scroll bars).